import matplotlib.pyplot as plt 
import numpy as np          

from matplotlib.font_manager import FontProperties
pic_font = FontProperties(fname=r"/System/Library/Fonts/PingFang.ttc", size=12) 

t = [1,2,3,4,5] 
height = 1.75
s = [70,69,71,71.5,72]
for i in range(0, 5):
    s[i] = s[i] / height / height

plt.plot(t, s, 'r+-')       
plt.ylim(20, 25)
plt.xlabel('时间 ', fontproperties=pic_font)     
plt.ylabel('BMI值', fontproperties=pic_font)    
plt.title('BMI 随 时间 变化曲线', fontproperties=pic_font)  

plt.show()
